Tuning coil shifter



Oct. 2, 1934. c. M. MURDOCK TUNING COI L SHIFTER .2 SheetsSheet 1Original Filed Nov. 24, 1931 JIMMzzrdavk,

INVEiNTOR Reiaued o... 2, 1934 TUNING COIL SHIF'I'EE' Charles M.Murdock, Haywood, Calif;

Original No. 1,873,658, dated August Serial-No. 577,121,Novemb'er :4,-1931. 'Application for reissue December 9, 1933, Serial No.

11 Claims. (Cl. 171- 119) The object: of the invention is to provide adevice adapted to hold a full set of the conventional interchangeablecoils employed. as tuners in radio apparatus to cover the full band of Ifrequencies from the low wave, through the broadcast band and above thelatter, so that the desired coil may be immediately put in circuit bymeans'exposed on the panel of the receiver; to provide a constructionfor interchangel able coils that will permit the inclusion of a selected'one in circuit with the same length of leads as any other one, so thatthere may not be the disadvantages resulting from switching arrangementsuch as where thecoils are cut into II and out of circuit by themanipulation of the switch; to provide a device of the nature describedin which there will be indicated on the front of the dial the particularcoil in circuit;

to provide a construction that will insure the retention of the selectedcoil in circuit; to pro vide'a contacting device that will insure firmcontact with the terminals of the coil connected in circuit; and to,provide generally a device of this nature which is of simple form, of, acharacter that may be manufactured at moderate expense, and of aconstruction susceptible of incorporation in conventional radioapparatus without material modification thereof.

-With this object in view the invention consists '80 in a constructionand combination of parts of which a preferred embodiment is illustratedin the accompanying drawings, but to which embodiment the invention isnot to bere stricted. Continued use in practice may suggest certain )6changes or alterations and the right is claimed .to make any changefalling within the scope of the appended claims. In the drawings: vFigure 1 is a side elev'atlonal view of the invention, the base andpanel 01' the connected instrument being shown in section, as well ascertain other parts,

Figure 2 is a top plan view of the structure of Figure 1,

15 Figure 3'is a bottom plan --view of the structure of Figure 1, thepanel being shown in section.

Figure 4 is a sectional view on the plane indicated by the line 44 ofFigure 1.

@541 Instead of a plurality of different coils for selective insertionin a receiving socket, or a multiple switch positionable to include anyone of a plurality of tuning coils in circuit, the invention providesformounting of the coils eniployed on a single movable table, such asthat plate and is indicated at 10. Movement of the table 10 is desiredto accomplish the connection in circuit of any, one of the coils. 11which are wound for different wave lengths, sothat the short wave,broadcast and higher bands may be covered. Movement of the table inthe-illustrated embodiment is accomplished by rotation, the table havinga king pin 12 joumaled in a support 14, the latter being mounted on thebase 15 of the radio apparatus and having a bracket portion 16 5 inwhich is journaled a shaft 17, the latter being disposed below the planeof the table and also having a bearing inthe front panel 19, exterior towhich the shaft 'is provided with a finger knob 20 by means of which itmay be rotated.

The shaft 17 constitutes actuating means for the table and to this endis provided on one extremity with a beveled gear 21, the latter meshingwith a beveled gear 22 mounted on the under face of the tableconcentrically with the I king pin 12. I

In the illustrated embodiment the coils 11 shown are of the detachabletype-and to 'provide for their being mounted on the table 10, the latteris provided with a plurality of sockets 23, preferably but notnecessarily spaced at uniform angular distances around,the table. Thetable being of insulated material, the sockets are secured to the tableas by cap screws 24, these cap screws passing through thetable andthread- 3 ing'into the socket in the coil pin receiving holes of thelatter. The cap screws thus serve as contact members on the under faceof the table, by reason of being connected with the pin receiving holeof the socket, so that one terminal of each winding on the coil iselectrically connected with oneof the cap screws 24.

Instead of sockets 23, the coils may be permanently attached to thetable with combined contacting and securing means such as the cap screws24.

None of the coils 11 is in circuit until the table is so positioned'forthe contact members 24 of any coil to be positioned above the springimpelled contact members 25 which are carried by a yieldingiy mountedinsulating plate 26. The plate 26 is hingedly-connected, as indicated at2'1, with the support 14 and rests upon-a compression spring 28 seatedat one end on the arm 29 extending from the support 14. The spring thusserves to raise the plate 26, but the height it may be elevated isdeterminedby the stop screw which through the free end of the providedwith clamp nuts 31 above and below the plate.

When the contact members 24 of any coil are in. position to engage thecontact members 25 of the plate'the,head of the stop screw engages in aseat'32 on'the under face of the plate, there being a seat properlypositioned with respect to each coil, so that the table may be retainedin circuit engagin position for any coil.

The contact members 25 consist of headedstuds slidably mounted inbushings 34 which are in turn mounted in the plate 26. Each contactmember 25 is individually yieldingly mounted by reason of a compressionspring 35 compressed between its head and the upper face of fitsattendant bushing.

Each bushing has. secured thereto a lug 36 by which connection .may bemade to appropriate of the radio apparatus by means of pigtail or otherflexible conductors.

In operating the invention rotation of the handle 20 serves to rotatethe table 10 and angular movement imparted to the table resultsindepressing .the plate 26 byreason of the head of being then disengagedfrom its which the head of thescrew slides against the under face ofthetable in the angular movement of the latter. Depression of the plate26, also permits the-contact members 24 being disengaged from thecontact members 25 and the coil which had previously been connected incircuit is thus disconnected and another connected in its place when thetable is brought to rest with the stop screw engaging the seat 32associated with the selected coil. I

, said carrier,

a flat outer surface, a stationary spring pressed lever opposite saidsurface, means for rotating sets of contacts flush with said surface forthe several coils of the carrier, 9. set of contact means fixed on saidlever concentrically with the other sets of contacts, a stop screw car-I ried by said lever and being wiped by said car- To provide for theoperator or use! being able' to determine visibly what particular coilis in circuit, the table is surrounded with an annular strip 3'1, thisconstituting a drum on-the pcriph eral face of which may be inscribedindicla visible through a window 38 and indicating to the operator theparticular coil in circuit.

The invention having been described what is claimed as new and usefulis:-

. sight opening, cumferential 1. A coil shifting device comprisin amovable table, a plurality of coils carried on said table, a stationarymember having contacts for connection in the circuit of radio apparatus,and means for effecting movement of the table to selectively positionany of the coils over said stationary member with its terminals in endengagement with the contacts of the latter, the stationary member havinga spring yieldingly impelling it toward the table, and the latchingmeans carried by said member and in the under face of the contactscarried by said member bein each sprin impelled vidually yieldable.

2.Inadevice asdescribeda casehavinga a turntable in said case, acirseries of coils seated on'the turntable, means for rotating theturntable, a stationary movable lever under said turntable, sets on saidlever, means on said lever wiping the under face of the turntable as thelatter turns and adapted to separate the lever contacts from the coilcontacts, and means whereby the other means may automatically andsuccessively halt the turntable as each coil is positioned opposite saidsight opening and for simultaneously contacting one set of coil contactswith the lever contacts. I;

3. In a timing'coil shiftingjapparatus, a rotatable carrier having coilsthereon and having to render them indirier as the latter rotates, forseparating the contac means from any of the set of contacts, and meanswhereby the stop screw halts the carrier automatically and releasablywhen each successive coil is successively positioned over the screw andwhereby the contact means automatically engage the set of contacts forthe last named coil.

4. In a tuning coil shifter apparatus, a turntable having acircumferential series of sets of contacts flush with its outer surface,a stationary set of contacts, manual means for rotating the turntable topresent each successive set of contacts over the stationary set, meansfor separating the,stationary set of contacts from the other sets as theturntable rotates, and means for automatically and releasedly haltingthe turntable and for contacting with any selective set of turntablecontacts. 5. In a device as described, a turntable, a series of socketmembers circ ferentially mounted on the inner face thereof, a series ofcoils having a detachable contact engagement with the several socketmembers, sets of contact points in the separate socket members extendingto the outer face of the turntable, a stationary set of contacts, meansfor rotating the turntable to move each set of contact points, and meansfor automatically moving the stationary set of contacts selectively intoabutting relation with any of the sets of contact points and forseparating them whilst they move towards the contact points. asdescribed the radially separated coils pending contacts for each coil,means rotating said table; a stationary set of contacts, meansyieldingly supporting said stationary set of contacts and means on saidsupporting means being constantly held in engagement with the table forinducing movement of the supporting means towards and from the table,for causing alternate engagement and disengagement of each set of coilscontacts with the stationary contacts as the table rotates and forhalting the table periodically while said sets of contacts engage.

'1. In a device as described a plurality of tuning coils, a panel boardhaving a window, means for successively positioning each coilselectively 130 opposite said window, a set of contacts carried by eachcoil, 2. set of stationary contacts spaced opposite to said window, andengageable with any selective set of contacts of any coil as it ispositioned opposite, said window, between which stationary contacts andsaid window each set of coil contacts moves en route to engage thestationary contacts, and means controlled by said with defirst means forautomatically moving the stationno ary sets of contacts into engagementwith the contacts of the selectively positioned coil.

- 8. In a device as described havinga panel board formed with a window,a set of contacts stationed opposite to said window, coils each of whichis movably positioned opposite to said window and carrying each a set offixed contacts against which said first set of contacts moves to-eflectautomatic engagement as the coil is so positionedand means for automat-150 the stationary set of contacts '100 combination of 115 a pluralityof tuning 1 5 I board for actuating'the table, a set of coils detachablymounted on one side of the table so as to move therewith, and havingseparate sets of contact points, a. stationary set of contacts locateddiametrically across said table from said window and movable towards theother side of the table to engage with any selective set of contactpoints stopping thereagainst, and means con trolled by the table forstopping the mentioned set of points and controlling the movement of thestationary set of contacts.

10. In a device as described, a base, a support thereon, a turntablejournaled in said support for rotation, and having "on its under side acircumferentially spaced apart series of notches-and also a set ofcontact pointsadjacent each notch,

tuning coils on the upper side of the turntable each carrying one set ofcontact points, a lever pivoted to said support and carrying a pin whoserounded head is yieldingly pressed against the underside of saidturntable as the latter rotates whereby to automatically enter any notchto releasedly halt the turntable, and a single set of contacts mountedon said lever automatically snapping into engagement with a selectiveset of coil contact points as the pin head enters a notch.

11. In a device as described, in combination a. manually oscillatableturntable carrying spaced surmounted coils, means fixed so as to extendradially of and under the turntable and so as to move towards and fromthe latter, an electrical circuit, means operable as the first meansmoves towards the turntable, in one direction, to stop the latter and tocause said circuit to be closed to one tuning 'coil, and meanscontrolled by said turntable for actuating the last-named movement ofthe first means and for causing the latter to move in a counterdirection to open the circuit to the mentioned coil.

CHARLES M. MURDOCK.

